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Area Forecast Discussion (AFD)

Issued by Houston/Galveston, TX (HGX)

FXUS64 KHGX 222328

Area Forecast Discussion
National Weather Service Houston/Galveston TX
628 PM CDT Sun Sep 22 2019

Generally a continued forecast of persistence considering the
overall wx pattern remains about the same. Remaining shra 
activity will dissipate in the next few hours, followed by sct 
redevelopment offshore later tonight, spreading inland during the
daylight hours Mon. Ceilings will mainly be VFR, but we've seen 
some intermittent late night thru mid morning 1500-2500ft decks 
(even some 500-1000ft cigs at UTS). Cannot rule out the same 
thing late tonight. 47


.PREV DISCUSSION... /ISSUED 344 PM CDT Sun Sep 22 2019/ 
A ridge will come to prevail across the Gulf Coast region for 
most of this week, resulting in a weather pattern typical of late 
summer for the area. While not completely dry, afternoon showers 
and thunderstorms are likely to be diminished for several days.

Towards the end of the week, ridging will weaken somewhat, and
will allow for an influx of moisture and increased rain chances.
The rain pattern is still expected to be dominated by daily
patterns and result in scattered showers and thunderstorms,
primarily in the late morning through early evening.

SHORT TERM [Through Monday]...
Scattered showers and isolated thunderstorms moving northward 
across SE Texas are expected to dissipate this evening with the 
loss of heating. High temperatures today are expected be in the 
upper 80s to low 90s, but will be cooler along areas receiving 
rain this afternoon. Low temperatures will range generally be in 
the mid 70s tonight with calm to light southeasterly winds. Mostly
tranquil weather conditions are expected tonight through early 
Monday morning with passing showers possible along the Gulf waters
and coastal areas. 

An upper level cutoff low over the Gulf of Mexico is expected to 
continue to move westward and into the eastern coasts of Mexico 
Monday. Additionally, a pulse of low level moisture is expected to 
move over the southeastern quadrant of the CWA early Monday morning, 
gradually spreading northwestward during the day. These two features 
should help support the development of shower and thunderstorm 
activity, however, area of high pressure in the mid levels could 
inhibit some this development. The latest HiRes Precip model run 
indicates activity moving along the Gulf waters overnight and early 
Monday morning, building further inland as the day progresses. Thus, 
kept the probability of showers moving along the coastal regions 
Monday morning, with showers and isolated thunderstorms expanding 
across the central and eastern portions of the forecast area during 
the afternoon. Periods of heavy rain, brief gusty winds, lightning 
and reduced visibility can be expected with the strongest storms. 
This activity is expected to dissipate in the evening with the loss 
of heating.

LONG TERM [Monday Night Through Sunday]...
A stacked ridge over the northern Gulf coast looks to dominate 
the bulk of the work week. Along with precipitable water falling 
to around the 25th percentile for September, I would expect 
rainfall to be harder to come by for the next several days. The 
ridge is centered to our east, placing us more on its western 
periphery. With subtle vort maxes rotating through, I don't expect
us to be totally dry this week, and expect isolated 
showers/storms at most to beat the odds.

Towards the end of the week, look for a northern stream trough to
dig deep enough to dent the Gulf ridging. With a greater weakness
in place and onshore flow bringing in an airmass with precipitable
water closer to 2 inches, shower and storm coverage should trend
upwards into the weekend.

Not much exciting going on here. Look for winds to largely fall 
in the 10-15 knot range; a little weaker during the day, a little 
stronger at night. SCEC conditions may emerge here and there 
through the week, but no particularly obvious targets stand out at
this point.

The persistent onshore winds will also result in increased tidal
levels and stronger rip currents. Astronomical levels are already
up to 2.0 feet above MLLW, and modeling puts the wind component on
top of that to at least 3.0 feet above MLLW for the next few days.
Because of this, we can probably expect the beach hazards
statement in place for today to be extended on the overnight

Most of the area's river gages have fallen below flood stage as 
water levels on the areas rivers continue to fall. The one 
exception is for Cedar Bayou near Crosby as flooding continues 
along the bayou. However, a technical glitch in the river warning 
has prompted us to replace that river warning with an areal flood 
warning. This has no impact on the nature of the flooding along 
the bayou, but will allow us to display a warning that best 
represents the area threatened by floodwaters.


College Station (CLL)      75  93  73  93  70 /  10  20   0  10   0 
Houston (IAH)              76  90  74  90  72 /  20  40   0   0   0 
Galveston (GLS)            81  87  81  87  79 /  30  40   0  10  10